Overheating

[daiagaru2]

hello,it maybe a leaking hose this would more likely leak coolant than suck air in.is the waterpump actually pumping,even when you do replace a waterpump brand new there may be air in the pump preventing the water from ciculateing coolant thru the engine.sometimes a vacume pump is requred to get the air out.my other suggestion is that the thermostat is not functioning correctly preventing the flow of the coolant thru the waterpump,thus the system becomes preasurized and extremely hot and spitts the coolant thru the overflow and out into the overflow tank.if your rad is good you've covered all the other bases milling the block,milling the head at the same time making sure the surfaces are true and using brand new metal head gaskets .also,have you had these blocks magnafluxed along with the heads there may be a minute crack somewere causin this irritating endevor.thats all i got for now, i hope this helps.being as thorough as you sound i'd immagine you'll figure it out.if not i'll try to brainstorm a few fresh ideas.have a less frustating day,and don't let that crap defeat you.